sync branch rt-smart. (#6641)

* Synchronize the code of the rt mart branch to the master branch.
  * TTY device
  * Add lwP code from rt-smart
  * Add vnode in DFS, but DFS will be re-write for rt-smart
  * There are three libcpu for rt-smart:
    * arm/cortex-a, arm/aarch64
    * riscv64

Co-authored-by: Rbb666 <zhangbingru@rt-thread.com>
Co-authored-by: zhkag <zhkag@foxmail.com>

bsp/allwinner/libraries/drivers/SConscript

@@ -0,0 +1,39 @@
+# RT-Thread building script for component
+
+from building import *
+
+cwd     = GetCurrentDir()
+src     = ['drv_uart.c', 'drv_pin.c']
+
+CPPPATH = [cwd]
+
+if GetDepend('BSP_USING_WDT'):
+    src += ['drv_wdt.c']
+
+if GetDepend('BSP_USING_RTC'):
+    src += ['drv_rtc.c']
+
+if GetDepend('BSP_USING_I2C'):
+    src += ['drv_i2c.c']
+
+if GetDepend('BSP_USING_SPI'):
+    src += ['drv_spi.c']
+
+if GetDepend('BSP_USING_PWM'):
+    src += ['drv_pwm.c']
+
+if GetDepend('BSP_USING_LCD'):
+    src += ['drv_lcd.c']
+    src += ['lcd_cfg.c']
+
+group = DefineGroup('Drivers', src, depend = [''], CPPPATH = CPPPATH)
+
+objs = [group]
+
+list = os.listdir(cwd)
+
+for item in list:
+    if os.path.isfile(os.path.join(cwd, item, 'SConscript')):
+        objs = objs + SConscript(os.path.join(item, 'SConscript'))
+
+Return('objs')